WABCO RSC Maintenance Manual

ANTI-LOCK BRAKING SYSTEM

(ABS) AND ELECTRONIC

STABILITY CONTROLS (ESC):

FOR E VERSION ECUs

MAINTENANCE MANUAL

Service Notes

Information contained in this publication was in effect at the time the publication

was approved for printing and is subject to change without notice or liability.

WABCO reserves the right to revise the information presented or to discontinue the

production of parts described at any time.

WABCO Maintenance Manual MM-0112 (Revised 07-18)

About This Manual

This manual contains maintenance procedures for WABCO’s

Anti-Lock Braking System (ABS), Roll Stability System (RSC),

Electronic Stability Controls (ESC) and Hill Start Aid (HSA).

Before You Begin

1. Read and understand all instructions and procedures before

you begin to service components.

2. Read and observe all Warning and Caution hazard alert

messages in this publication. They provide information that can

help prevent serious personal injury, damage to components,

or both.

3. Follow your company’s maintenance and service, installation

and diagnostics guidelines.

4. Use special tools when required to help avoid serious personal

injury and damage to components.

Hazard Alert Messages and Torque

Symbols

Read and observe all Warning and Caution hazard alert messages in

this publication. They provide information that can help prevent

serious personal injury, damage to components, or both.

WARNING

A Warning alerts you to an instruction or procedure that you

must follow exactly to avoid serious personal injury and

damage to components.

CAUTION

A Caution alerts you to an instruction or procedure that you

must follow exactly to avoid damage to components.

@ This symbol alerts you to tighten fasteners to a specified torque

value.

WARNING

To prevent serious personal injury, always wear safe eye

protection when you perform vehicle maintenance or service.

Release all air from the air systems before you remove any

components. Pressurized air can cause serious personal

injury.

CAUTION

When welding on an ABS- or ABS/ATC-equipped vehicle is

necessary, disconnect the power connector from the ECU to

prevent damage to the electrical system and ABS/ATC

components.

How to Obtain Additional Maintenance,

Service and Product Information

Visit wabco-auto.com to access and order additional information.

Contact WABCO North America Customer Care at 855-228-3203

(United States and Canada); 001-800-889-1834 (Mexico).

If Tools and Supplies are Specified in

This Manual

Call Meritor’s Commercial Vehicle Aftermarket at 888-725-9355 to

obtain Meritor tools and supplies.

Asbestos and Non-Asbestos Fibers

i

WABCO Maintenance Manual MM-0112 (Revised 07-18)

ASBESTOS FIBERS WARNING

The following procedures for servicing brakes are recommended to reduce exposure to

asbestos fiber dust, a cancer and lung disease hazard. Material Safety Data Sheets are

available from WABCO.

Hazard Summary

Because some brake linings contain asbestos, workers who service brakes must understand the

potential hazards of asbestos and precautions for reducing risks. Exposure to airborne asbestos

dust can cause serious and possibly fatal disea

ses, including asbestosis (a chronic lung disease)

and cancer, principally lung cancer and mesothelioma (a cancer of the lining of the chest or

abdominal cavities). Some studies show that the risk of lung cancer among persons who smoke

and who are exposed to asbestos is much great

er than the risk for non-smokers. Symptoms of

these diseases may not become apparent for 15, 20 or more years after the first exposure to

asbestos.

Accordingly, workers must use caution to avoid creating and breathing dust when servicing brakes.

Specific recommended work practices for red

ucing exposure to asbestos dust follow. Consult your

employer for more details.

Recommended Work Practices

1. Separate Work Areas. Whenever feasible, service brakes in a separate area away from other

operations to reduce risks to unprotected persons. OSHA has set a maximum allowable level of

exposure for asbestos of 0.1 f/cc as an 8-hour time

-weighted average and 1.0 f/cc averaged over

a 30-minute period. Scientists disagree, however, to what extent adherence to the maximum

allowable exposure levels will eliminate the risk of disease that can result from inh

aling asbestos

dust. OSHA requires that the following sign be posted at the entrance to areas where exposures

exceed either of the maximum allowable levels:

DANGER: ASBESTOS

CANCER AND LUNG DISEASE HAZARD

AUTHORIZED PERSONNEL ONLY

RESPIRATORS AND PROTECTIVE CLOTHING

ARE REQUIRED IN THIS AREA.

2. Respiratory Protection. Wea

r a respirator equipped with a high-efficiency (HEPA) filter

approved by NIOSH or MSHA for use with asbestos at all times when servicing brakes, beginning

with the removal of the wheels.

3. Procedures for Servicing Brakes.

a. Enclose the brake assembly within a negative pr

essure enclosure. The enclosure should be

equipped with a HEPA vacuum and worker arm sleeves. With the enclosure in place, use the

HEPA vacuum to loosen and vacuum residue from the brake parts.

b. As an alternative procedure, use a catch

basin with water and a biodegradable,

non-phosphate, water-based detergent to wash the brake drum or rotor and other brake

parts. The solution should be applied with low pressure to prevent dust from becoming

airborne. Allow the solution to flow between the

brake drum and the brake support or the

brake rotor and caliper. The wheel hub and brake assembly components should be thoroughly

wetted to suppress dust before the brake shoes or brake pads are re

moved. Wipe the brake

parts clean with a cloth.

c. If an enclosed vacuum system or brake washing equipment is not available, employers may

adopt their own written procedures for servicing brakes, provided that the exposure levels

associated with the employer

’s procedures do not exceed the levels associated with the

enclosed vacuum system or brake washing equipment. Consult OSHA regulations for more

details.

d. Wear a respirator equipped with a HEPA filter approved by NIOSH or MSHA for use with

asbestos when grinding or machining b

rake linings. In addition, do such work in an area with

a local exhaust ventilation system equipped with a HEPA filter.

e. NEVER use compressed air by itself, dry brushing, or a vacuum not equipped with a HEPA

filter when cleaning brake parts or assemblies. NEVER use carcinogenic solvents, fla

mmable

solvents, or solvents that can damage brake components as wetting agents.

4. Cleaning Work Areas. Clean work areas with a vacuum equipped with a HEPA filter or by wet

wiping. NEVER use compressed air or dry sweeping to clean work areas. When you empty vacuum

cleaners an

d handle used rags, wear a respirator equipped with a HEPA filter approved by NIOSH

or MSHA for use with asbestos. When you replace a HEPA filter, wet the filter with a fine mist of

water and dispose of the used filter with care.

5. Worker Clean-Up. After servicing

brakes, wash your hands before you eat, drink or smoke.

Shower after work. Do not wear work clothes home. Use a vacuum equipped with a HEPA filter to

vacuum work clothes after they are worn. Launder them separately. Do not shake or use

compressed air to remove dust from work clothes.

6. W

aste Disposal. Dispose of discarded linings, used rags, cloths and HEPA filters with care,

such as in sealed plastic bags. Consult applicable EPA, state and local regulations on waste

disposal.

Regulatory Guidance

References to OSHA, NIOSH, MSHA, and EPA, which are regulatory agencies in the United States,

are made to provide further guidance to employers and workers employed within the United States.

Employers and workers employed outside of the United S

tates should consult the regulations that

apply to them for further guidance.

NON-ASBESTOS FIBERS WARNING

The following procedures for servicing brakes are recommended to reduce exposure to

non-asbestos fiber dust, a cancer and lung disease hazard. Material Safety Data Sheets

are available from WABCO.

Hazard Summary

Most recently manufactured brake linings do not contain asbestos fibers. These brake linings may

contain one or more of a variety of ingredients, including glass fibers, mineral wool, aramid fibers,

ceramic fibers and silica that can present health risks if inhaled.

Scientists disagree on the extent

of the risks from exposure to these substances. Nonetheless, exposure to silica dust can cause

silicosis, a non-cancerous lung disease. Silicosis gradually reduces lung capacity and efficiency

and can result in serious brea

thing difficulty. Some scientists believe other types of non-asbestos

fibers, when inhaled, can cause similar diseases of the lung. In addition, silica dust and ceramic

fiber dust are known to the State of California to cause lung cancer. U.S. and internation

al

agencies have also determined that dust from mineral wool, ceramic fibers and silica are potential

causes of cancer.

Accordingly, workers must use caution to avoid creating and breathing dust when servicing brakes.

Specific recommended

work practices for reducing exposure to non-asbestos dust follow. Consult

your employer for more details.

Recommended Work Practices

1. Separate Work Areas. Whenever feasible, service brakes in a separate area away from other

operations to reduce risks to unprotected persons.

2. Respiratory Protection. OSHA has set a maximum allowable level of exposure for silica of

0.1 mg/m3 as an 8-hour time-weighted average. Some manufacturers of non-asbestos brake

linings recommend that exposures to other ingredients found in non-asbestos brake linings be

kept below 1.0 f/cc as an 8-hour time-weighted average. Scientists dis

agree, however, to what

extent adherence to these maximum allowable exposure levels will eliminate the risk of disease

that can result from inhaling non-asbestos dust.

Therefore, wear respiratory protection at all times during brake servicing, beginning with the

removal of the wheels. Wear a respirator equipped with a high-efficiency (HEPA) filter approved by

NIOSH or MSHA, if the exposure levels may exceed OSHA or manufacturers’ recommended

maximum levels. Even when exposures are expected

to be within the maximum allowable levels,

wearing such a respirator at all times during brake servicing will help minimize exposure.

3. Procedures for Servicing Brakes.

a. Enclose the brake assembly within a negative pressure enclosure. The enclosure shoul

d be

equipped with a HEPA vacuum and worker arm sleeves. With the enclosure in place, use the

HEPA vacuum to loosen and vacuum residue from the brake parts.

b. As an alternative procedure, use a catch basin with water and a biodegradable,

non-phosphate, water-based detergent to wash the brake drum or rotor and other brake

parts. The solution should be applied with low pressure to prevent dust from becoming

airborne. Allow the solution to flow between the brake drum and the

brake support or the

brake rotor and caliper. The wheel hub and brake assembly components should be thoroughly

wetted to suppress dust before the brake shoes or brake pads are removed. Wipe the brake

p

arts clean with a cloth.

c. If an enclosed vacuum system or brake washing equipment is not available, carefully clean

the brake parts in the open air. Wet the parts with a solution applied with a pump-spray bottle

that creates a fine mist. Use a solution containing water, and, if available, a biodegradable,

non-phosphate, water-based detergent. The wheel hub and brake assembly components

should be thoroughly wetted to suppress dust before the brake shoes or brake pads a

re

removed. Wipe the brake parts clean with a cloth.

d. Wear a respirator equipped with a HEPA filter approved by NIOSH or MSHA when grinding or

machining brake linings. In addition, do such work in an area with a local exhaust ventilation

system equipped with a HEPA filter.

e. NEVER

use compressed air by itself, dry brushing, or a vacuum not equipped with a HEPA

filter when cleaning brake parts or assemblies. NEVER use carcinogenic solvents, flammable

solvents, or solvents that can damage brake components as wetting agents.

4. Cleaning Work Areas. Clean work areas with a vacuum equipped with a HEPA filter or by wet

wiping. NEVER use compressed air or dry sweeping to clean work areas. When you empty vacuum

cleaners and handle used rags, wear a respirator equipped with a HEPA filter approved by NIOSH

or MSHA, to minimize

exposure. When you replace a HEPA filter, wet the filter with a fine mist of

water and dispose of the used filter with care.

5. Worker Clean-Up. After servicing brakes, wash your hands before you eat, drink or smoke.

Shower after work. Do not wear work clothes home. Use a vacuum equipped with a HEPA filter to

vacuum work clothes after they are worn. Launder them separately. Do not shake or use

compressed air to remove dust from work clothes.

6. Waste Disposal. Dispose of discarded linings, used rags, cloths and HEPA filters with care,

such as in sealed plastic bags. C

onsult applicable EPA, state and local regulations on waste

disposal.

Regulatory Guidance

References to OSHA, NIOSH, MSHA, and EPA, which are regulatory agencies in the United States,

are made to provide further guidance to employers and workers employed within the United States.

Employers and workers employed outside of the United S

tates should consult the regulations that

apply to them for further guidance.

Contents

pg. pg.i Asbestos and Non-Asbestos Fibers

1 Section 1: Introduction

Contents

Anti-Lock Braking System (ABS)

System Components

Electronic Control Unit (ECU)

Wheel Speed Sensing Systems

2 Pressure Modulator Valves

3 Active Braking Valves (ABV)

Brake Pressure Sensor (BPS)

Steering Angle Sensor (SAS)

4 Electronic Stability Control (ESC) Module

Trailer Modulator Valve

Off-Road ABS Switch

ATC Switch

Blink Code Switch

System Configuration

6

Section 2: Stability and Safety Enhancement

Systems

ATC

ATC Components

ATC Switch

7 Roll Stability Control (RSC)

RSC Components

9 Electronic Stability Control (ESC)

ESC Components

11 Hill Start Aid (HSA)

HSA Components

12 Drag Torque Control

Lift Axle Capability

13

Section 3: Diagnostics, Troubleshooting and

Testing

General

Maintenance Information

ABS Indicator Lamp

14 Diagnostics

TOOLBOX™ Software Diagnostics

17 Blink Code Diagnostics (ABS Only)

23 Testing

Wheel Speed Sensor Testing

25 Modulator Valve Testing

29 Active Braking Valves (ABV) Testing

32 Brake Pressure Sensor Testing

33 ESC CAN Network Testing

ESC Module Testing

35 Steering Angle Sensor (SAS) Testing

37 ECU Circuit Testing

J1939 Serial Communications Testing

39

Section 4: Component Replacement

Component Removal and Installation

Wheel Speed Sensors

40 Modulator Valves

41 Active Braking Valves (ABV)

42 ABS Valve Packages

44 Active Braking Valve on the ABS Valve Package

45 Electronic Control Unit (ECU)

46 Steering Angle Sensor (SAS) — WABCO Only

47 Electronic Stability Control (ESC) Module

48 Brake Pressure Sensor

50

Section 5: System Configurations

System Configuration Layouts

52

Section 6: Wiring Diagrams and Connectors

ECU Connector Pin Assignments

65

Section 7: SPN, SID, FMI Fault Codes

SPN, SID, FMI Diagnostic Trouble Code List

94

Section 8: Appendix I

Reconfiguration Procedure

How to Reconfigure an ECU (E Version)

TOOLBOX™ Software

95 Manual Reconfiguration

97

Section 9: Appendix II

E4 ESC End of Line Calibration Procedure

104

Section 10: Appendix III

E8 ESC End of Line Calibration Procedure

108

Section 11: Appendix IV

Aftermarket Programming

Aftermarket Programming Procedures

116 Aftermarket Programming Failure Codes List

1 Introduction

1

WABCO Maintenance Manual MM-0112 (Revised 07-18)

1 Introduction

Contents

This manual contains service information for the following systems.

앫 E version WABCO Anti-Lock Braking System (ABS)

앫 Automatic Traction Control (ATC)

앫 Roll Stability Control (RSC)

앫 Electronic Stability Controls (ESC) for trucks, tractors and buses

The ABS version is marked on the ECU. Figure 1.1. If you cannot

identify the ECU version installed on your vehicle, contact WABCO

North America Customer Care at 855-228-3203.

Figure 1.1

For Additional Information

Diagnostic and testing procedures for other ECU versions can be

found in the following manuals.

앫 C version ECUs — Maintenance Manual 28, Anti-Lock Braking

Systems (ABS) for Trucks, Tractors and Buses

앫 D version ECUs — Maintenance Manual 30, Anti-Lock Braking

Systems (ABS) for Trucks, Tractors and Buses

Refer to the following manuals for Trailer ABS diagnostics and

information.

앫 Maintenance Manual 33, Easy-Stop™ Trailer ABS

앫 Maintenance Manual MM-0180, Enhanced Easy-Stop™ Trailer

ABS with PLC

Anti-Lock Braking System (ABS)

ABS is a system designed to provide and maintain the best possible

traction and steering control during an extreme braking event.

During a potential wheel lock event, the ABS ECU, using information

provided by the wheel speed sensors, sends a signal(s) to the

appropriate modulator valve(s) to hold, apply or release the brakes

as needed. ABS works automatically, the driver does not have to

select this feature.

System Components

Electronic Control Unit (ECU)

The ECU is the control center or “brain” of the ABS, RSC and ESC

systems. It receives information from the sensors, processes data

and sends signals to modulators and active braking valves to

achieve different tasks. Depending on the system and vehicle

configuration, ECUs are available for cab- or frame-mounted

applications and are divided into Basic Cab, Universal Cab, Frame

and Advance Frame models. RSC and ESC systems are only

available on universal and advance frame ECUs. Figure 1.2.

Figure 1.2

Wheel Speed Sensing Systems

Wheel speed sensing systems consist of a tooth wheel mounted on

the hub or rotor of each monitored wheel and a speed sensor

installed with its end against the tooth wheel. The sensor

continuously sends wheel speed information to the ECU. A sensor

clip holds the sensor in place and against the tooth wheel.

Figure 1.3.

Figure 1.1

4010603a

Figure 1.2

UNIVERSAL

ECU

FRAME-MOUNTED

ECU

BASIC

ECU

4003974a

1 Introduction

2

WABCO Maintenance Manual MM-0112 (Revised 07-18)

Figure 1.3

The type of axle determines sensor mounting location.

앫 Steering axle sensors are installed in the steering knuckle or in a

bolted-on bracket.

앫 Drive axle sensors are mounted in a block attached to the axle

housing or in a bolted-on bracket.

Check the wheel speed sensors for correct alignment and

adjustment. Apply lubricant to the sensor and sensor clip whenever

wheel-end maintenance is performed. Make sure tooth wheels are

free of contaminants. Refer to Section 3 and Section 4 for more

information.

Pressure Modulator Valves

A modulator valve controls air pressure to an affected wheel-end

brake during an ABS, RSC or ESC event to reduce speed and

prevent wheel lock up. Modulator valves are also used during ATC

events to properly gain traction on the affected wheel end.

Figure 1.4.

Figure 1.4

A modulator valve is usually located on a frame rail or cross member

near the brake chamber or as part of a valve package. A valve

package combines two modulator valves, a service relay

(Figure 1.5) or quick release valve (Figure 1.6), and depending on

the vehicle configuration, an active braking valve (ABV).

Figure 1.5

Figure 1.6

Easy Listening Tip!

To ensure the ABS valves are working — just listen! Figure 1.7.

WARNING

Park the vehicle on a level surface. Block the wheels to

prevent the vehicle from moving. Support the vehicle with

safety stands. Do not work under a vehicle supported only by

jacks. Jacks can slip or fall over. Serious personal injury and

damage to components can result.

1. Turn on the ignition.

2. Wait for the ABS indicator lamp to come on.

3. Listen for the valves to click or puff/chuff air in the order shown

in Figure 1.7.

Figure 1.3

Figure 1.4

1002009b

SENSOR

CLIP

SENSOR

TOOTH

WHEEL

BAYONET-STYLE

CONNECTOR

AIR IN

(PORT 1)

AIR OUT

(PORT 2)

4003992b

PRODUCT

IDENTIFICATION TAG

Figure 1.5

Figure 1.6

x

1002011a

472 500 30. 0

MADE IN GERMANY

001 20/98

1003359a

1 Introduction

3

WABCO Maintenance Manual MM-0112 (Revised 07-18)

Figure 1.7

NOTE: In previous versions of ABS, the valves are cycled

diagonally. Diagonal cycling does not occur with E version ABS.

Active Braking Valves (ABV)

Active Braking Valves, sometimes referred to as ABVs or 3/2 valve,

are solenoid valves used for active braking during ATC, RSC or ESC

events. Depending on system configurations, ABVs can be located

in the front axle braking system, rear axle braking system and/or the

trailer service brake system. Figure 1.8.

Figure 1.8

Brake Pressure Sensor (BPS)

The Brake Pressure Sensor or BPS is part of the RSC, ESC and HSA

system. It provides the system with the driver’s brake demand. The

sensor can be located in the primary or secondary delivery circuit

depending on the application. Figure 1.9.

Figure 1.9

Steering Angle Sensor (SAS)

The Steering Angle Sensor (SAS) is part of the ESC system. The SAS

delivers the driver’s steering input (steering wheel position) to the

ECU using a dedicated ESC system internal data link. The ECU

supplies the sensor with voltage and ground. The SAS must be

calibrated using diagnostic tools whenever it is replaced, or when

any vehicle steering components are replaced or adjusted. Refer to

Section 8. Figure 1.10.

Figure 1.7

3 1

2 4

4 1

3 6

2 5

1002006d

4M CHANNEL

CAB

CURBSIDE

CAB

CURBSIDE

6M CHANNEL

Figure 1.8

Figure 1.9

4007846a

SOLENOID VALVE

(ACTIVE BRAKING VALVE)

CABLE

4006870a

27 FT-LB

(36.6 Nm)

TORQUE

1 Introduction

4

WABCO Maintenance Manual MM-0112 (Revised 07-18)

Figure 1.10

Electronic Stability Control (ESC) Module

The ESC module is part of the ESC system. It measures the vehicle

yaw rate as well as vehicle lateral acceleration. The ESC module

includes part of the ESC control algorithm. It exchanges data with

the ECU via the ESC system internal data link. The ECU supplies the

module with voltage and ground. The ESC module must be

initialized by diagnostic tools whenever the ECU or the ESC module

is replaced. Refer to Section 8. Figure 1.11.

Figure 1.11

Trailer Modulator Valve

In some stability control applications, an additional modulator valve

(the same as what is used for ABS modulation) will be located in the

trailer control line downstream of the 3/2 solenoid valve used to

control the trailer.

Off-Road ABS Switch

On some vehicles, an off-road ABS switch can be included. The

off-road ABS function improves vehicle control and helps reduce

stopping distances in off-road conditions or on poor traction

surfaces such as loose gravel, sand and dirt.

ATC Switch

A vehicle manufacturer might offer an ATC switch to control the ATC

function. Depending on the vehicle ECU configuration for the switch,

there are two function options.

앫 Deep snow and mud option

앫 ATC momentary override option

Refer to Section 2 for more information regarding these features.

Blink Code Switch

A vehicle manufacturer might offer a Blink Code switch to obtain

simple troubleshooting information. Refer to Section 3 for more

information about Blink Codes.

System Configuration

The system configuration is defined by the number of wheel end

sensors and modulator valves. There are three common system

configurations used with E version ECUs. Refer to Section 5 for more

system configurations.

앫 4S/4M (4 wheel speed sensors, 4 modulator valves)

앫 6S/4M (6 wheel speed sensors, 4 modulator valves)

앫 6S/6M (6 wheel speed sensors, 6 modulator valves)

Each system configuration can have features such as ATC, HSA,

RSC or ESC. See Figure 1.12 and Figure 1.13 for an example.

Figure 1.10

Figure 1.11

4006873a

4010604a

WARNING

DO NOT MOVE OR RELOCATE

1 Introduction

5

WABCO Maintenance Manual MM-0112 (Revised 07-18)

Figure 1.12

Figure 1.13

Figure 1.12

1002004h

WHEEL SPEED

SENSORS

ABS

MODULATOR

VALVES

ABS

MODULATOR

VALVE

ABS

MODULATOR

VALVE

RELAY

VALVE

WHEEL SPEED

SENSORS

ECU

4S/4M CONFIGURATION — ABS ONLY

AIR LINES

ELECTRICAL LINES

LAMPS

QUICK

RELEASE

VALVE

Figure 1.13

VALVE PACKAGE

INSTALLATION (REAR)

AIR LINES

LAMPS (UP TO

THREE: ABS,

TRAILER ABS, ATC)

LAMPS

4S/4M ABS/ATC

ATC VALVE

1002004g

VALVE PACKAGE

INSTALLATION (FRONT)

2 Stability and Safety Enhancement Systems

6

WABCO Maintenance Manual MM-0112 (Revised 07-18)

2 Stability and Safety Enhan ce ment Sy stem s

ATC

Automatic Traction Control is available as an option on all E version

ECUs and is standard on most. ATC helps improve traction in low

traction road conditions. ATC reduces the potential of jackknifing

caused by excessive wheel spin during acceleration or in curves.

ATC works automatically in two different ways.

A. When one drive wheel is spinning at a different speed than the

other, ATC momentarily applies the brake until traction is

regained.

B. When both drive wheels are spinning on a poor-traction

surface, ATC automatically reduces engine power to attain

optimum tire-to-road traction.

ATC will automatically turn on and off. Driver input is not required to

turn this feature on. If the vehicle experiences a traction control

event, the ATC indicator lamp will come on, indicating ATC is active.

The light turns off when the event has ended. Figure 2.1.

Figure 2.1

NOTE: Some vehicle manufacturers may refer to ATC as Anti-Spin

Regulation (ASR).

If ATC is installed, there will be an indicator lamp on the vehicle dash

or instrument panel marked ATC, ASR, or potentially Stability

Control, depending on the application.

ATC Components

ATC uses the base ABS components plus an active braking valve

that can be installed with individual modulator valves, or installed as

part of the rear valve package.

When installed with individual modulator valves, the active braking

valve is mounted on the frame or cross member, near the rear of the

vehicle.

When it is part of the rear valve package, the active braking valve is

attached to the relay valve. Figure 2.2.

Figure 2.2

ATC Switch

If the vehicle manufacturer offers an ATC switch to control the ATC

functionality, there are two common types of configuration settings

as follows.

앫 Deep snow and mud option: This function helps to increase

available traction on extra soft surfaces like snow, mud or gravel,

by slightly increasing the permissible wheel spin.

앫 ATC momentary override option: This function allows the

driver to momentarily disable/override ATC for the duration of the

ignition cycle.

When either option is in use, the ATC indicator lamp blinks

continuously to inform the driver. Figure 2.3.

Figure 2.1

NORMAL

VEHICLE

OPERATION

EXCESSIVE WHEEL

SPIN ATC

OPERATIONAL

(ATC LAMP COMES ON)

1002015a

(ATC LAMP IS OFF)

WHEELS

STOP

SPINNING

(ATC LAMP GOES OUT)

Figure 2.2

4010605a

2 Stability and Safety Enhancement Systems

7

WABCO Maintenance Manual MM-0112 (Revised 07-18)

Figure 2.3

Switch and lamp locations as well as ATC switch configuration will

vary depending on the vehicle make and model. Please check with

the vehicle manufacturer for correct information.

Here’s how the ATC switch works.

NOTE: Turning off the ignition will also deactivate either ATC

function.

Roll Stability Control (RSC)

Roll stability control is an option designed to assist drivers in

managing the conditions that may result in vehicle rollovers. When

RSC senses conditions that may result in a rollover, it may reduce

engine torque, engage the engine retarder, apply pressure to the

drive axle brakes and may modulate the trailer brakes to slow the

vehicle down. Depending on the application and vehicle

configuration, the steer axle brakes may be applied as well.

Similar to ATC, RSC works automatically. The driver does not have to

select this feature. Unlike ATC, RSC cannot be turned off by the

driver.

RSC Components

RSC uses many of the same components used by ABS/ATC

including modulator valves, active braking valves and wheel speed

sensors. RSC ECUs are different from ABS ECUs as they contain an

internal accelerometer that measures and updates the lateral

acceleration of the vehicle and compares it to a critical threshold at

which rollover may occur.

Depending on the vehicle manufacturer, RSC ECUs have orientation

on the XX/YY or ZZ axis. For correct operation and the best

performance, verify the ECU is correctly leveled and securely

mounted. Figure 2.4, Figure 2.5 and Figure 2.6.

Figure 2.4

Figure 2.3

Driver Action

System

Response

Function

Active

Not

Active

Press ATC switch ATC lamp blinks

continuously

X

Press ATC switch

again

ATC lamp stops

blinking

X

1002018a

Figure 2.4

4010606a

Z ± 2°

X ± 2°

DRIVING

DIRECTION

+92°

-2°

Y

XX Orientation

2 Stability and Safety Enhancement Systems

8

WABCO Maintenance Manual MM-0112 (Revised 07-18)

Figure 2.5

Figure 2.6

Certain vehicle configurations can have an additional active braking

valve for trailer service brakes, an active braking valve for front axle

brakes and a brake pressure sensor.

The active braking valve for trailer braking is a stand-alone valve

that is not available as part of the ABS/ATC valve package.

Depending on the application, a modulator valve may be located

downstream of the solenoid valve. Figure 2.7.

WARNING

RSC helps reduce the tendency of the vehicle to roll over when

cornering or changing directions, however, IT CAN NOT

PREVENT ALL ROLLOVERS FROM OCCURRING.

When operating the vehicle, always use safe driving techniques. The

driver is always the most important factor in safe vehicle operation.

Figure 2.5

Figure 2.6

4010607a

Z ± 2°

Y ± 2°

DRIVING

DIRECTION

+2° ± 90°

ZZ Orientation

4010608a

0° ± 2°

DRIVING

DIRECTION

0° ± 92°

X

Z

YY Orientation

2 Stability and Safety Enhancement Systems

9

WABCO Maintenance Manual MM-0112 (Revised 07-18)

Figure 2.7

Electronic Stability Control (ESC)

Electronic Stability Control (ESC) combines the rollover prevention of

Roll Stability Control (RSC) with directional stability in order to keep

the vehicle traveling on its intended path by providing spinout and

drift out control.

Like RSC, ESC is automatic. It becomes active when the system

senses imminent directional or roll instabilities, often before the

driver is aware. You will notice a difference in the vehicle when

stability control is functioning, but you should continue to drive as

normal and provide any additional needed corrections.

You may again notice a reduction in engine torque and additional

deceleration from the retarder, if so equipped. You also may notice

individual or all brakes applying depending on whether the vehicle is

in a roll or directional control event.

ESC Components

ESC is built from the ABS platform and uses many of the same

components as ATC and RSC. An active braking valve to control the

front axle brakes, a pressure sensor, an ESC module and a Steering

Angle Sensor (SAS) are required in addition to the components

necessary for RSC. Figure 2.8 and Figure 2.9. These components

are also described in the following section.

Note that for ESC applications on a non-towing vehicle (straight

truck), the trailer active braking valve is not required.

The ESC ECU is available in both Cab- and Frame-mounted

versions. The Universal Cab-Mounted ECU with ESC is an upgraded

version of the current Universal ABS ECU with a fourth connector

containing the necessary inputs/outputs required for full stability

control. The Frame-Mounted Advance ECU with ESC is an upgraded

version of the current ABS Frame-Mounted ECU with six additional

pins on both the X1 and X2 connectors of the ECU. These ECUs

support 4S4M, 6S4M and 6S6M vehicle configurations and are

compatible with 12V electrical systems. For pinout information, refer

to Section 6 of this manual.

Figure 2.7

4007813a

VALVE PACKAGE

INSTALLATION (REAR)

AIR LINES

ELECTRICAL LINES

4S/4M RSC/ATC

(ALSO AVAILABLE IN

6S CONFIGURATIONS)

VALVE PACKAGE

INSTALLATION (FRONT)

LAMPS

TRAILER STABILITY

CONTROL

MODULATOR

(OPTIONAL)

PRESSURE

SENSOR

(OPTIONAL)

ATC VALVE

FRONT AXLE

ACTIVE

BRAKING

VALVE

(OPTIONAL)

TRACTOR

PROTECTION

VALVE

TRAILER ACTIVE

BRAKING

VALVE

2 Stability and Safety Enhancement Systems

10

WABCO Maintenance Manual MM-0112 (Revised 07-18)

The ESC ECU contains parameter settings which are specific to a

vehicle configuration validated by WABCO Engineering. It is

imperative that the correct ECU is installed on your vehicle in

service. Contact WABCO or your respective vehicle OEM with any

questions regarding ESC ECU. Figure 2.8 and Figure 2.9.

Figure 2.8

NOTE: ESC modules are installed by the OEM close to the vehicle

center of gravity. Depending on the vehicle manufacturer, the ESC

module might face towards the front of the vehicle or rear. For

correct operation and the best performance, verify the ESC module

is correctly leveled and securely mounted according to OEM

specifications. Do not move the module to a different location as this

will affect the system performance.

Figure 2.8

4010609a

± 5°

-5°

Z

+2°

-2°

Y

+2°

-2°

X

2 Stability and Safety Enhancement Systems

11

WABCO Maintenance Manual MM-0112 (Revised 07-18)

Figure 2.9

Hill Start Aid (HSA)

Hill Start Aid (HSA) supports select automated manual transmissions

in reducing/totally eliminating the rolling back of the vehicle while

launching on a grade. When requested from the transmission, HSA

holds pressure in the service brakes of all axles of the towing vehicle

when the vehicle is standing still. HSA will hold pressure for a

maximum of three seconds following full release of the brake pedal.

Communication between the transmission and the ECU takes place

via the J1939 data link.

HSA grade threshold parameters may be modified in the

Transmission ECU. These parameters must be reviewed with the

transmission manufacturer prior to making any modifications in

order to ensure safe operation.

HSA Components

HSA is available on ABS ECUs with E4.4 software revision or higher.

Same as ESC, HSA is built from the ABS platform and uses many of

the same components as ATC and RSC. HSA uses the front axle

active braking valve as well as the rear active braking valve to help

maintain the pressure trapped during HSA activation.

A pressure sensor provides the system with the driver’s brake

demand. The measured pressure is used by HSA to set the trapped

pressure and/or activate the HSA function.

The vehicle manufacturer can provide an HSA switch multiplexed

through the dashboard or hard wired for momentary HSA

deactivation.

An HSA lamp, either hard wired or multiplexed, provides the driver

with a visual indication of system deactivation and/or active fault. If

the lamp is hard wired, it must be an incandescent lamp or LED with

a resistor to prevent the ECU from setting a fault code.

A failure detected on any of these components will lead to no HSA

availability. To troubleshoot the HSA, refer to Section 3 –

Diagnostics, Troubleshooting and Testing.

Figure 2.9

4007814a

VALVE PACKAGE

INSTALLATION (REAR)

AIR LINES

ELECTRICAL LINES

4S/4M ESC/ATC

(ALSO AVAILABLE IN

6S CONFIGURATIONS)

ESC

MODULE

LAMPS

TRAILER ACTIVE

BRAKING

VALVE

TRAILER STABILITY

CONTROL

MODULATOR

(OPTIONAL)

PRESSURE

SENSOR

ATC VALVE

SAS

FRONT AXLE

ACTIVE

BRAKING

VALVE

TRACTOR

PROTECTION

VALVE

2 Stability and Safety Enhancement Systems

12

WABCO Maintenance Manual MM-0112 (Revised 07-18)

Drag Torque Control

The ABS ECU has the ability to send a message to the engine to

increase engine RPM to prevent drive axle lock-up, if the vehicle is

on a downhill grade and in the incorrect gear.

Lift Axle Capability

Certain six sensor ABS ECUs with ATC allow third axle sensors to be

installed on a lift axle. These ECUs will not log a fault for the axle

being in the raised position while the vehicle is moving.

3 Diagnostics, Troubleshooting and Testing

13

WABCO Maintenance Manual MM-0112 (Revised 07-18)

3 Diagn ostics, Troublesho oting and Testin g

General

Maintenance Information

There is no regularly scheduled maintenance required for the

WABCO ABS, ATC, RSC or ESC systems. However, this does not

change current vehicle maintenance requirements.

앫 Lamp Check: To ensure the ABS tractor lamp is operating,

drivers should check the lamp every time the vehicle is started.

When the vehicle is started, the ABS lamp should come on

momentarily. If it does not come on, it could mean a burned-out

bulb.

앫 ABS Wheel Speed Sensors: Check the wheel speed sensor

adjustment and lubricate the sensor and sensor clip whenever

wheel-end maintenance is performed. Use only

WABCO-recommended lubricant, as specified in Section 4.

ABS Indicator Lamp

Two ABS indicator lamps, one for tractor and one for trailer, let

drivers know the status of the system. Figure 3.1. The tractor ABS

lamp is also used to display tractor blink code diagnostics. The

location of the ABS indicator lamps varies depending on the make

and model of the vehicle.

Figure 3.1

ATC and RSC/ESC functions may share the same dash indicator

lamp. Therefore, understanding how the ABS and ATC/RSC/ESC

lamps work is very important.

앫 If the vehicle is equipped with ATC, but not RSC/ESC, when the

ignition is turned to the ON position, the ABS and ATC lamps will

light for approximately three seconds, and then both lamps will

turn off simultaneously. Figure 3.2.

앫 If the vehicle is equipped with ATC and RSC/ESC, when the

ignition is turned to the ON position, the ABS and ATC/RSC/ESC

will both light but the ATC/RSC/ESC lamp will stay lit briefly after

the ABS lamp goes out.

Figure 3.2

The ABS indicator lamp works as follows:

NOTE: If the ECU senses a tractor ABS fault during normal vehicle

operation, the ABS indicator lamp will come on and stay on.

Figure 3.1

1002000a

Figure 3.2

ATC

ABS

Both lamps come

on at ignition ON

and turn off after

approximately three

seconds. Vehicle

equipped with

ABS and ATC.

ATC

ABS

Both lamps come

on at ignition ON.

ATC/RSC/ESC lamp

stays on briefly after

ABS lamp goes out.

Vehicle equipped

with ABS, ATC

and RSC/ESC.

4005299d

ATC

ABS

ATC

3 Diagnostics, Troubleshooting and Testing

14

WABCO Maintenance Manual MM-0112 (Revised 07-18)

Diagnostics

NOTE: Blink code diagnostics are not compatible with E8 software

versions.

Use any of the following methods to diagnose E version ECUs:

앫 Wabco TOOLBOX™ Software, a PC-based diagnostic and

testing program that runs in Microsoft Windows



XP, Vista,

Windows 7 or Windows 8 operating system.

앫 Blink Codes. Refer to the information in this section.

앫 OEM Diagnostic Displays. Refer to the vehicle operator’s manual.

If you have any questions about system diagnostics, please contact

WABCO North America Customer Care at 855-228-3203.

TOOLBOX™ Software Diagnostics

For complete instructions for installing and using TOOLBOX™

Software, refer to the User’s Manual posted on wabco-na.com.

WABCO TOOLBOX™ Software provides computer-based diagnostic

capabilities for the complete range of WABCO vehicle control

systems. The program provides the following functions:

앫 Displays both static (e.g., ECU number) and dynamic (e.g.,

RPMs) information from the system under test.

앫 Displays both active and stored system faults, as well as the

appropriate repair instructions.

앫 Activates system components to verify system integrity, correct

component operation and installation wiring.

NOTE: For E8 software versions, TOOLBOX™ 12 or higher is

required.

To display E version ABS, RSC, ESC or HSA faults:

1. Connect the computer to the vehicle:

앫 Attach the USB/serial cable from your computer’s USB or

serial port to the adapter.

앫 Attach the Deutsch diagnostic cable from the adapter to the

vehicle. Figure 3.3.

Figure 3.3

2. Select the TOOLBOX™ Software icon from the desktop or from

the Windows



Start Menu to display the Main Menu.

3. Adapter Selection

Verify the TOOLBOX™ Software is set for the device and

communication protocol that will be used.

To access “Adapter Selection” for TOOLBOX™ Software 11 or

newer, click on “Utilities” from the main TOOLBOX™ page or

under “System Setup” in “J1707/PLC TOOLBOX” from the

main TOOLBOX page. Figure 3.5.

Ignition ON Normal Operation ABS lamp comes on at ignition

momentarily for a bulb check,

then goes out.

System is OK.

After servicing ABS

components

ABS lamp does not go out at

ignition.

When vehicle is driven at speeds

above 4 mph (6 km/h), lamp

goes out. System is OK.

Off-road ABS operation. Refer

to the off-road ABS information

in this section.

ABS lamp flashes during vehicle

operation.

The vehicle’s normal ABS

function is being modified due to

road conditions.

Existing fault or lamp issue ABS lamp does not go out at

ignition.

Lamp does not go out at speeds

above 4 mph (6 km/h) — a fault

may exist in the ABS system or

lamp is permanently shorted.

ON

OFF

1002005a

Figure 3.3

4010610a

TO VEHICLE

DEUTSCH

CONNECTOR

USB OR

SERIAL CABLE

ADAPTER

3 Diagnostics, Troubleshooting and Testing

15

WABCO Maintenance Manual MM-0112 (Revised 07-18)

To access “Comport Settings” for TOOLBOX™ Software

versions prior to TOOLBOX™ Software 11, click on “System

Setup” from the main TOOLBOX™ page. Figure 3.6.

Make sure the “Vendor:” and “Adapter:” drop-downs are set

for the device being used and set the “Protocol:” drop-down to

J1708 OR J1939 according to the system you will be

communicating through, and click “OK”. Figure 3.4.

Figure 3.4

NOTE: When switching between J1939 and J1708

communications with TOOLBOX™ Software 11, the vehicle

ignition must be cycled between sessions to correctly

communicate with the ECU.

NOTE: TOOLBOX™ Software must be connected to the vehicle

and the vehicle ignition must be ON in order to display

information. If unable to communicate with the ECU:

앫 Verify device and data link connections are secure.

앫 Verify the device is RP1210A compliant and that the

comport settings (Vendor, Protocol, Adapter) in

TOOLBOX™ Software are correct.

앫 Verify the device software and firmware is up to date.

앫 Check all the powers and grounds coming to the ECU

including load testing.

앫 Check J1587 circuit at the ECU and the data link connector.

앫 Check J1939 circuit at the ECU and the data link connector.

4. Depending on the software version used, there will be two

options to communicate with the vehicle:

앫 If using TOOLBOX™ 11 or higher and a vehicle with

Software ECU E4.4b or higher, diagnostics over J1939

communications can be possible. Figure 3.5.

NOTE: E8 software versions will only communicate over

J1939.

앫 J1708 communications are possible with any TOOLBOX™

Software version and any D or E Version ECU. Figure 3.6.

NOTE: When switching between J1939 and J1708

communications, vehicle ignition must be cycled between

sessions to correctly communicate with ECU.

Figure 3.5

Figure 3.6

Figure 3.4

4011997a

Figure 3.5

Figure 3.6

4010611a

WABCO TOOLBOX 11.5

WABCO TOOLBOX

4010612a

WABCO TOOLBOX J1 708 Diagnostics

3 Diagnostics, Troubleshooting and Testing

16

WABCO Maintenance Manual MM-0112 (Revised 07-18)

5. In the Main Menu, select J1939 Tractor ABS or J1708

TOOLBOX™, then Tractor ABS. The ABS Main Screen will

appear. Figure 3.7 and Figure 3.8.

Figure 3.7

Figure 3.8

6. Select Display from the top menu.

7. From the pull-down menu, select Faults or Diagnostic

Trouble Codes. This will open the Fault Information screen.

Figure 3.9 and Figure 3.10.

Figure 3.9

Figure 3.10

8. A description of the fault, the number of times the fault

occurred, the system identifier (SID), the failure mode (FMI) and

Suspect Parameter Number (SPN) are all displayed in the fault

information window. Basic repair instructions for each fault are

also provided. More detailed information about SID and FMI

troubleshooting and repair is provided in the following section

as well as the SID FMI table.

Figure 3.7

Figure 3.8

4010613a

WABCO Toolbox - Pneumatic ABS Diagnostics

WABCO Pneumatic ABS

4010614a

WABCO ABS

Figure 3.9

Figure 3.10

4010615a

4010616a

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